DE1768242A1 - Process for the production of allyl chloride or methallyl chloride - Google Patents

Description

Process for the production of allyl chloride or methallyl chloride

Various processes are already known for the production of allyl chloride. You win that on a technical scale Allyl chloride mainly through the high-tea-rate chlorination of propylene. It is very disadvantageous in this process that only half of the chlorine used can be used for the production of allyl chloride; the other Half of the chlorine is converted into hydrogen chloride. It is lost for the production of allyl chloride if the hydrogen chloride does not form chlorine in a further reaction stage is oxidized.

In order to be able to better utilize the chlorine used, one has already tried to use allyl chloride directly by oxychlorination from propylene old to produce hydrogen chloride and oxygen. Two methods have become known for this purpose.

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One works at high temperatures with lithium or Magnesium chloride as catalysts, the other for something lower temperatures with tellurium or tellurium bonds. Both processes produce water, which forms hydrochloric acid, which forms part of the hydrogen chloride is lost due to the corrosive properties of hydrochloric acid, additional technical measures are required

Furthermore, allyl chloride can be omitted by known methods Allyl alcohol or its formic acid ester by reaction with hydrochloric acid or hydrogen chloride in the presence of relative produce large amounts of zinc chloride. That is why allyl alcohol and allyl formate are used in a technical process out of consideration, since they are technically much more difficult to access than allyl chloride Implementation is relatively slow and leads to relatively low yields of allyl chloride,

A process for the preparation of allyl chloride or methallyl chloride has now been found, which is characterized in that allyl acetate or methallyl acetate is used in the presence of 0.01 to 10% by weight of a catalyst consisting of a mixture of copper salts and. Lewis acid at temperatures between 20 ° and 200 ⁰ C, preferably above 45 C with hydrogen chloride.

The acetic acid that is formed at the same time is also recovered practically quantitatively. According to the invention Allyl acetate is used according to a known process from propylene, oxygen and acetic acid with palladium catalysts produced in a technically simple manner in the oasis phase. The allyl acetate or nethallyl acetate used is practically quantitative in allyl chloride or methallyl chloride convicted.

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The amount of the catalyst mixture should be 0.01 to 10 wt .- #, based on the allyl acetate or methallyl acetate used, be; Advantageously, however, 0.1 to 5 weight percent of the catalyst mixture is used the mixing ratio of copper salt and Lewis acids can be varied as required within the above limits When it comes to practical implementation, these are particularly important Proven catalyst mixtures that consist of equal parts of the two components, or in which the copper salt is included in the deficit

The Lewis acids used in the process according to the invention are used for example iron (III) chloride, aluminum chloride or Aluminum bromide, zinc chloride, titanium (IV) chloride, beryllium chloride, zirconium (IV) chloride, antimony (V) chloride and bismuth (III) chloride in embossing. Of these, iron (III) chloride, Aluminum chloride and zinc chloride are particularly preferred All of these compounds are preferably used in anhydrous form.

The copper salts used for the process according to the invention both salts of monovalent and divalent copper or mixtures of salts of monovalent and divalent copper Copper used Salts of copper suitable for this purpose are, for example, the chlorides, bromides, sulfates and acetates, The chlorides of copper are mostly used for the process according to the invention. The anhydrous salts are preferred of copper for the production of the allyl chloride according to the invention or methallyl chloride used

Surprisingly, the catalytic effect of the Catalyst mixtures used according to the invention are not additive from the individual activities of the catalyst components. The copper salts have only a very low catalytic effect on their own, although the Lewis acids are catalytically much more effective, they cannot be used on their own for a technical process, since this is If significant amounts of catalyst would be required. Further

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the Lewis acids alone would be caused by side reactions, e.g. due to the formation of diallyl ether, the yields of allyl chloride or methallyl chloride have a considerable adverse effect. Draw the catalyst mixtures used according to the invention on the other hand duroh an excellent activity and selectivity which guarantee practically quantitative conversions.

The reaction temperature is maintained at the erflndungsgemäfien process between 20 and 200 ⁰ C · Advantageously, but will operate at temperatures above 45 ⁰ C, when the resulting allyl chloride is to be immediately separated from the reaction mixture "

The reaction is preferably carried out in the liquid phase or in the so-called countercurrent process carried out · Many of the catalyst components, especially the Lewis acids, dissolve in allyl acetate. In contrast, the copper salts are in allyl acetate less soluble, so that they are partly in are in suspended form; however, the proportion of copper salts dissolved in the allyl acetate is sufficient catalytic effectiveness.

However , the process according to the invention can also be carried out in an inert solvent, for example in a chlorinated hydrocarbon such as hexachloroethane or pentachloroethane or tetrachloroethane. In this case, it is twice as good to choose a solvent whose boiling point is higher than that of acetic acid. However, the inventive method can also be carried out in the oasis phase. In this case, the gaseous reaction components are passed over the fixed catalyst mixture, which may be applied to a suitable carrier material.

The expediently dried hydrogen chloride becomes gaseous used. It is either passed into the solution or the suspension of the catalyst in allyl acetate or introduces it in the upstream of the trickling down solution or suspension of catalyst mixture and allyl acetate, unreacted Hydrogen chloride is recycled and used again, so that it is practically completely used,

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The method according to the invention is preferably carried out under atmospheric pressure carried out; however, it is also under perform increased or reduced pressure.

The allyl chloride formed is expediently immediately removed from the reaction framework, whereby a complete! approach is guaranteed. An addition of hydrogen chloride on allyl chloride could not be observed under the reaction conditions according to the invention. the The allyl chloride is separated off using known methods, such as fractional distillation or condensation,

As one of various procedural options for the discontinuous production of allyl chloride the following method has proven itself:

Dryer gaseous hydrogen chloride is passed into the left hand in a flask, low-boiling allyl acetate (Kp, ca! ⁰ 03.5 C), in which the catalyst components are dissolved or suspended. The allyl chloride formed (Kp, ca, 45 ° C) distills off immediately if one keeps the temperature of the reflux condenser mounted above the condensation temperature of the allyl chloride and below the boiling point of the AUylacetats, for example at 50 ⁰ C. As the reaction progresses, the acetic acid (boiling point approx. X18.5 ° C) accumulates in the sump and can be used again for the production of allyl acetate.

As already mentioned, the method according to the invention can be used also perform continuously. For this purpose, the allyl acetate is left with the dissolved or suspended catalyst mixture trickling against a stream of hydrogen chloride; the allyl chloride formed can be distilled off in a simple manner »The acetic acid is placed in a lower distillation unit removed, while the catalyst can be drawn off with the remaining acetic acid in the bottom.

The allyl compounds used or formed tend to be not for polymerization under the reaction conditions according to the invention. In analogous catfish can be methallyl-

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aoetat (Kp. 124 oa ⁰ C.) of methallyl chloride (Kp. oa. T2 ° C) prepared.

The advantage of the method according to the invention is that that one allyl chloride or methallyl chloride in practically quantitative yield from the technically easily accessible

Allyl acetate or Methaliy.laeetat duroh reaction with hydrogen chloride can manufacture; also arise in the inventive Process no chlorine losses and no corrosion problems due to the known processes resulting aqueous hydrochloric acid.

Example 1;

100 g of allyl acetate (1.0 mol) are heated to 80 ° C. together with a mixture of 1 g of iron (III) chloride and 0.5 g of copper chloride. 0.4 mol of hydrogen chloride gas per hour is passed into the hot mixture. After a few minutes, Allylohlorld is distilled off over a reflux cooler heated to approx. 50 ° C in accordance with the dosage of hydrogen chloride, and this is condensed in a Liebig cooler. After the above 2.5 hours, the yield of allyl chloride is 75.4 g (0.985 mol) »98.5 % of theory.

Example 2:

100 g allyl acetate (1.0 mole) are boiled with 0.5 g of anhydrous aluminum chloride and 0.5 g Kupferaoetat under reflux and thereby introduced 0.4 mol of hydrogen chloride per hour · About one heated to about 50 ⁰ C RUckflufikühler distilled to short tent allyl chloride. After a reaction time of about 2.5 hours, the yield of Allylohlorld is 75 g (0.98 mol) - 98.0 % of theory.

Example 3:

100 g allyl acetate (1.0 mole) are heated at 80 ⁰ C with a Oemisoh from 1 g of anhydrous zinc chloride and 1 g of copper chloride. 0.4 mol of hydrogen chloride gas per hour is passed into the hot mixture. Distilled after a few minutes

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a to about 5O ⁰ C heated reflux condenser from the corresponding Chlorwaseerstoffdosierung allyl chloride, which is condensed in a LiebigkUhler · The yield of allyl chloride is 75 »* g (0.985 moles) - 98.5 Ji of theory.

Example 4;

iOO g allyl acetate (1.0 mole) are heated together with 0,058wasserfreiem Zinkohlorid and 0.05 g of copper chloride at 90 ⁰ C. 0.1 mol of hydrogen chloride gas per hour is passed into the hot solution. After a few minutes over distilled from a heated to approximately 50 ⁰ C RUckfluBkUhler according to the hydrochloric dosage allyl chloride, which is condensed in a Llebigktihler. The yield of allyl chloride is 75 # 1 g (0.982 mol) - 98.2 % of theory.

Example 5t

100 g of allyl acetate (1.0 mol) are refluxed together with a mixture of 4.5 g of anhydrous iron (III) chloride and 0.5 g of copper chloride and 0.4 mol of hydrogen chloride is passed in per hour. A heated to about 50 ⁰ C RückfluflkUhler A1IyI-ohlorid distilled off after a short tent. The yield of allyl chloride is 75.0 g (0.98 mol) - 98.0 % of theory.

Example 6t

100 g of allyl acetate (1.0 mol) are heated ^{to 80 °} C. together with a mixture of 8.5 g of anhydrous zinc chloride and 1.5 g of copper chloride. 0.4 mol of hydrogen chloride gas per hour is passed into the hot mixture. After several minutes, distilled over a heated to about 50 ⁰ C reflux condenser according to the allyl chloride from hydrochloric dosage, which is condensed in a LlebigkUhler. The yield of allyl chloride is 75 g (0.98 mol) - 98.0 % of theory,

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according to Example 1, 100 g of allyl acetate (1.0 mol) with 0.4 mol of chlorine fiber per hour mr and used instead of the mixture of 1.0 ζ F, lse; * - (III) chloride and 0.5 r,

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Copper chloride only 1.0 g of Elsen- (III) -chloride as a catalyst, so distilled Compared to the amount of hydrogen chloride metered in, significantly less allyl chloride than Example 1 * After a reaction time of about 2.5 hours, the yield of allyl chloride is only 24, 0 g «31.4 % of theory If the experiment is continued, the yield increases to approx. 50 % of theory after 5 hours; however, the rate of reaction becomes progressively slower, so that an extension of the Versuohes beyond 5 hours no longer leads to a significant increase in the yield. At the same time, considerable amounts of by-products are formed

If in the above experiment the 1.0 g iron (III) chloride used as a catalyst is replaced by 1.0 g zinc chloride under otherwise unchanged conditions, the yield of allyl chloride after a reaction time of approx. 2.5 hours is 28, 0 g, corresponding to approx. 36.6 % of theory «

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Claims (3)

Claims 1. A process for the preparation of allyl chloride or methallyl chloride, characterized in that allyl acetate or methallyl acetate in the presence of 0.01 to 10 wt. Ji of a catalyst consisting of a mixture of copper salts and Lewis acid at temperatures between 20 ° to 200 ⁰ C, preferably above ^ 5 ° C # with hydrogen chloride. 2. The method according to claim 1, characterized in that one the reaction of allyl acetate or kethallyl acetate in the presence of 0.1 to 5% by weight of a catalyst, consisting from a mixture of a copper salt and a Lewis acid carried out. 3. The method according to claim 1 and 2, characterized in that the reaction of allyl acetate or Hethftllylacetat makes in an inert solvent. 109839/1792